Boccole Sinclair per misurare l'headspace dei vostri bossoli , compatibile con i corpi comparatori Sinclair e Hornady.
 
Alcuni calibri compatibili :300 WSM (Winchester Short Mag), 270 WSM (Winchester Short Mag), 7 mm WSM (Winchester Short Magnum), 325 WSM (Winchester Short Mag), 6.5/300 WSM (Wincester Short Mag), 25/300 WSM (Winchester Short Mag)